GDI color depth?

  • Thread starter Thread starter RobT
  • Start date Start date
R

RobT

I'll admit, that I don't do a lot of GDI+ programming and I'm sure this is
an easy answer. I'm trying to draw a couple of shapes in a web site. I can
display them just fine, but on some of the fill colors are pixelated. Is
there a way to render these colors at a better color depth?

Dim bmp As Bitmap
bmp = New Bitmap(200, 200)
Dim g As Graphics
g = Graphics.FromImage(bmp)
g.Clear(Color.White)
g.SmoothingMode = SmoothingMode.AntiAlias
Dim brsh As SolidBrush
brsh = New SolidBrush(Color.DarkGoldenrod)
g.FillPie(brsh, 10, 10, 50, 50, 0, 360)

Thanks
 
RobT said:
I'll admit, that I don't do a lot of GDI+ programming and I'm sure this is
an easy answer. I'm trying to draw a couple of shapes in a web site. I
can display them just fine, but on some of the fill colors are pixelated.
Is there a way to render these colors at a better color depth?

Dim bmp As Bitmap
bmp = New Bitmap(200, 200)
Dim g As Graphics
g = Graphics.FromImage(bmp)
g.Clear(Color.White)
g.SmoothingMode = SmoothingMode.AntiAlias
Dim brsh As SolidBrush
brsh = New SolidBrush(Color.DarkGoldenrod)
g.FillPie(brsh, 10, 10, 50, 50, 0, 360)
Click to expand...

Take a look at the different constructors of the 'Bitmap' class. In
addition, take a look at the different overloads of the 'Save' method. Note
that some image formats, such as GIF, only support a certain number of
colors in the image making dithering necessary.
 
Thanks for the pointers. I did modify the Save method to be jpeg instead
and that helps.

bmp.Save(Response.OutputStream, ImageFormat.Jpeg)

Now, is there a way to reduce the amount of compression of the jpeg so the
image is sharper? I(I have some other lines, text etc in my output). The
antialias looks fine...I'm pretty sure the compression is too high.

Thanks!
 
RobT said:
Thanks for the pointers. I did modify the Save method to be jpeg
instead and that helps.

bmp.Save(Response.OutputStream, ImageFormat.Jpeg)

Now, is there a way to reduce the amount of compression of the jpeg
so the image is sharper? I(I have some other lines, text etc in my
output). The antialias looks fine...I'm pretty sure the compression
is too high.
Click to expand...

Depending on your target audience, png could be a suitable file format.

Andrew
 
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